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G2 PowerPC Core Reference Manual
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MOTOROLA
that falls outside typical user-level software requirements. The VEA describes the
memory model for an environment in which multiple processors or other devices
can access external memory, and defines aspects of the cache model and cache
control instructions from a user-level perspective. The resources defined by the
VEA are particularly useful for optimizing memory accesses and for managing
resources in an environment in which other processors and devices can access
external memory.
Operating environment architecture (OEA)—The OEA defines supervisor-level
resources typically required by an operating system. The OEA defines the memory
management model, supervisor-level registers, and exception model.
Implementations that conform to the OEA also conform to the UISA and VEA.
Note that some resources are defined more generally at one level in the architecture and
more specifically at another. For example, conditions that cause a floating-point exception
are defined by the UISA, while the exception mechanism itself is defined by the OEA.
For ease in reference, topics in this book are presented in the same order as the
Programming Environments Manual.
Topics build on one another, beginning with a
description and complete summary of the G2 core register model (including the G2_LE
core specifics) and followed by the instruction set model and progressing to more specific,
architecture-based topics regarding the cache, exception, and memory management
models. As such, chapters may include information from multiple levels of the architecture.
(For example, the discussion of the cache model uses information from both the VEA and
the OEA.)
The PowerPC Architecture: A Specification for a New Family of RISC Processors
defines
the architecture from the perspective of the three programming environments and remains
the defining document for the PowerPC architecture. For information about ordering
Motorola documentation, see “Suggested Reading” on page xxxiv.
The information in this book is subject to change without notice, as described in the
disclaimers on the title page of this book. As with any technical documentation, it is the
readers’ responsibility to be sure they are using the most recent version of the
documentation. For more information, contact your sales representative.
To locate any published errata or updates for this reference manual, refer to the world-wide
web at http://www.motorola.com/semiconductors.
A list of major differences between the MPC603e microprocessor, the G2 core, and the
G2_LE core are provided in Table 1-6. Note that the G2 core has similar functionality as
the MPC603e. However, the minor differences between them are documented by footnotes.
F
Freescale Semiconductor, Inc.
n
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